Non-woven fiber batt has a demonstrated usefulness in a wide variety of applications. This material has been used in manufacturing scouring pads, filters, and the like, but is particularly useful as a filler material in various personal comfort items such as stuffing in furniture, mattresses and pillows, and as a filler and insulation in comforters and other coverings. One of the inherent characteristics of fiber batt is its cushioning ability due to the large amount of air space held within the batt material. The air space defined within the fiber batt acts as a thermal insulation layer, and its ready displaceability allows support in furniture, mattresses and pillows.
Typically, the fiber batt is produced from a physical mixture of various polymeric fibers. The methods for manufacturing the batt are well known to those skilled in the art. Generally, this method comprises reducing a fiber bale to its individual separated fibers via a picker, which "fluffs" the fibers. The picked fibers are homogeneously mixed with other separated fibers to create a matrix which has a very low density. A garnet machine then cards the fiber mixture into layers to achieve the desired weight and/or density. Density may be further increased by piercing the matrix with a plurality of needles to drive a portion of the retained air therefrom.
A resilient structure such as a seat, a furniture back or a sleeping surface must be able to support a given load, yet have sufficient resilience, or give, to provide a degree of comfort. For these structures, a densified heat bonded low melt fiber batt may be used to form an inner core, or as a covering. To provide the necessary support, a certain fiber density must be built into the fiber batt. If the fiber density is too high, the seat cushion or mattress will have sufficient rigidity but it will be too firm. If the fiber mass is less dense, it will be more comfortable. However, it will not be as durable and will be more susceptible to flattening out after use. Thus, while fiber batting has a number of well-recognized advantages, it is difficult to achieve a high degree of structural support and/or comfort for a resilient structure with a covering or core made from a densified heat bonded low melt fiber batt.
To minimize these limitations, it is common to combine a fiber batt with an interconnected wire lattice. For instance, mattresses often include a wire lattice sandwiched between two layers of fiber batting. The wire lattice provides a high degree of structural rigidity. Resiliency can be built into the wire lattice by including coil or leaf springs at various locations. To do this, the lattice may include a plurality of internal coils interconnected by border wire and anchoring springs.
While a resilient structure with an interconnected wire lattice of this type has many desirable features, it requires a relatively large quantity of steel. Moreover, its manufacture and construction also requires relatively complex machinery to form and interconnect the steel. The overall cost of a typical mattress of this type reflects the relatively high quantity of steel used to make the support lattice and the complexity of the required machinery.
Additionally, for some resilient structures with an interconnected lattice, including mattresses, it is desirable to provide more support in strategic areas. This option further increases the costs associated with manufacture, due to the variation in the lattice structure and/or assembly at these areas with enhanced rigidity. While the higher costs associated with these more complex machines may be economically justified for mattresses, which have standard sizes and shapes and can be made in mass quantity, it usually cannot be justified for a number of other nonstandard sized resilient structures, such as seat cushions, furniture backs and the like. As a result, the size and shapes of resilient structures with enhanced rigidity have been limited.